Wrong ESMTP with internal server name

[André Koppany]

HI,

our Proxmox Mail Gateway is running on a VM with a internal IP and hostname (mg.example-dc).

The public MX address (mg.example.com) will be forwarded via a firewall to the internal PGM VM.

The problem is that in the ESMTP message, the internal name will be used:
220-mg.example-dc ESMTP Proxmox

How can we change in general that PMG uses the public MX address when it will be connected by foreign mail servers?
Is there any config for that?

If we want to setup TLS, could be this a problem?

Best,

André

 

[Stoiko Ivanov]

not 100% sure which piece of information you want to change - but either set the hostname of your PMG to the external name:
* /etc/hostname (only the part before the first '.')
* /etc/resolv.conf (the first searchdomain is used as the domainname)
* /etc/hosts
see:
https://pmg.proxmox.com/pmg-docs/pmg-admin-guide.html#_configuration_files_overview

else you can change most more specific things in the postfix config, by using the templateing system:
https://pmg.proxmox.com/pmg-docs/pmg-admin-guide.html#pmgconfig_template_engine

If we want to setup TLS, could be this a problem?

In most situations I'd say the hostnames present in the certificates is not verified by SMTP servers

i hope this helps!